After harvesting of cones used for beer production, the remaining hop vegetative biomass requires disposal. The hop plant contains bioactive compounds in all its parts-cones, leaves, and roots-exhibiting interesting antioxidant, antiviral, and antibacterial properties. In this work, extracts obtained from hop leaves, a plant material often neglected in the hop cultivation, have been investigated; the qualitative UHPLC-MS/MS and GC-TOF-MS characterization revealed the presence of bioactive compounds such as polyphenols, α- and β-acids and terpenes are present. The extract retained antioxidant activity, as verified by Folin-Ciocalteu, DPPH, ABTS and FRAP assays, and demonstrated some antimicrobial activity when combined with antibiotics, particularly against Gram-positive bacterial strains. Additionally, the extracts showed an ability to interact with proteins as human insulin, amyloid beta peptide, mucin and bovine serum albumin (BSA), has been detected, indicating their potential to counteract inflammatory processes and protect against Alzheimer's disease. These findings suggest that hop vegetative biomass, typically considered waste, can be potentially transformed into a valuable resource with applications in various fields, from nutraceuticals to pharmaceuticals and cosmetics, aligning with a circular economy perspective.

(1) Background: In recent years, the consumption of sprouts, thanks to their high nutritional value, and the presence of bioactive compounds with antioxidant, antiviral and antibacterial properties, is becoming an increasingly widespread habit. Moringa oleifera Lam. (Moringa) seems to be an inexhaustible resource considering that many parts may be used as food or in traditional medicine; on the other hand, Moringa sprouts still lack a proper characterization needing further insights to envisage novel uses and applications. (2) Methods: In this study, a rapid and easy protocol to induce the in vivo and in vitro germination of Moringa seeds has been set up to obtain sprouts and cotyledons to be evaluated for their chemical composition. Moreover, the effects of sprouts developmental stage, type of sowing substrate, and gibberellic acid use on the chemical characteristics of extracts have been evaluated. (3) Results: Moringa seeds have a high germinability, both in in vivo and in vitro conditions. In addition, the extracts obtained have different total phenolic content and antioxidant activity. (4) Conclusions: This research provides a first-line evidence to evaluate Moringa sprouts as future novel functional food or as a valuable source of bioactive compounds.

The demand for bioactive secondary metabolites of natural origin is increasing every day. Micropropagation could be a strategy to respond more quickly to market demands, regardless of seasonality. This research aims to evaluate in vitro-grown plants of two hop varieties, namely Columbus and Magnum, as a potential source of bioactive compounds. The extracts were characterized in terms of total phenolic content by a Folin–Ciocalteu assay and antioxidant capacity by DPPH^•, ABTS⁺, and FRAP assays. The bioactive compound profile of the extracts from both varieties was determined by using UPLC-ESI-QqQ-MS/MS. The results confirmed richness in (poly)phenols and other secondary metabolites of the in vitro-grown hop plantlets. Thirty-two compounds belonging to the major families of phytochemicals characteristic of the species were identified, and twenty-six were quantified, mainly flavonoids, including xanthohumol and isoxanthohumol, phenolic acids, as well as α- and β-acids. This study confirms the validity of in vitro-derived hop plantlets as source of bioactive compounds to be used in the nutraceutical, pharmaceutical, and food industries.

(1) Background: Humulus lupulus L. plants constitute a rich source of bioactive compounds. The synthesis of bioactive compounds in plants is often triggered by the activation of secondary metabolism, which can be induced by biotic or abiotic elicitors. In vitro, the effect of the elicitors can be studied in a controlled environment and in a small space, independently of seasonal variations. Cytokinins are frequently used in plant tissue culture for bud regeneration, branching and shoot elongation due to their role in cell division enhancement. This study aimed to investigate the effects of different cytokinins on the growth parameters, total (poly)phenolic content and antioxidant capacity of in vitro-grown hop plants to evaluate hop vitro-derived biomass as a potential source of bioactive compounds. (2) Methods: unimodal hop (cvs. Cascade and Columbus) explants were cultured on media enriched with four cytokinins (kinetin, 6-benzylaminopurine, meta-topolin and 6-(γ,γ-dimethylallylamino)-purine) at four concentrations. (3) Results: A genotype-dependent response to different cytokinins was encountered. (4) Conclusions Columbus explants could root in culture media auxin-free, providing valuable opportunities for commercial nurseries. Moreover, cytokinins were confirmed to be valuable elicitors to stimulate the bioactive compound biosynthesis in micropropagated hop plants, making them a precious source for various industries.

(1) Background: Traditionally, hop is propagated using rhizome fragments or herbaceous stem cuttings. Micropropagation, therefore, offers a viable alternative for the large-scale production of healthy, genetically uniform plants, regardless of the season and within confined spaces. A temporary immersion system (TIS) facilitates plant propagation by alternating immersions of microcuttings in liquid culture medium with dry periods, preventing gas accumulation through forced ventilation. (2) Methods: In this study, the response of hop plantlets, cv. Columbus, cultured in media with and without sucrose, in solid and liquid culture systems (Plantform^TM bioreactor), was evaluated, considering its effect on morpho-physiological parameters, on the total phenolic content, and on antioxidant capacity. Moreover, to make the TIS more efficient, the effect of immersion duration (three and six minutes every twelve hours) was evaluated. (3) Results: The presence of sucrose in the culture medium improved plant proliferation in both culture systems tested: solid and liquid (particularly for explants immersed for three minutes). In the TIS, plantlets with a higher antioxidant capacity were obtained when sucrose-free culture medium was used. (4) Conclusions: This study confirms the efficacy of the TIS as a hop propagation method but also as a valid tool to produce biomass to be used as a source of bioactive compounds.

Nowadays, tomato, a commercially important crop, is increasingly cultivated in a soilless cultivation system to counteract climate change. Normally, this system uses cocopeat as a substrate, but its high cost and environmental impact have led to growing interest in alternatives like biochar (BC). In addition, biostimulants, such as wood distillate (WD), a pyrolysis by-product, are increasingly being used to improve fruit yield and quality. BC was used to partially replace (2% and 5%) cocopeat in growth bags for soilless tomato cultivation. Moreover, WD (3 mL/L) was distributed in the substrate every two weeks. The effect of BC and WD on tomato plant growth, fruit quality, and substrate microbial community was investigated. The integration of BC and WD into a soilless growing system for tomato cultivation can improve the fruit quality and influence the microbial activity of the substrate. Replacing part of the cocopeat in the substrate with BC and using an agri-waste-derived biostimulant represent a step forward in making agriculture more sustainable.